In addition to what Spook Louw wrote in his contribution, I think a good idea is to let others around you see when you truly enjoy some piece of content (a song, a youtube video, an image, a meme, etc.). It should be discoverable online for others to find and check out. This might require a bit more sophisticated software, a specialized app, etc. It would be like sharing something you like on social media, just instead real people around you would be able to see it, people, that you don't yet know.
So say you sit in a cafe and listen to music on Spotify, you discover a new song that you really enjoy (or just enjoying an old song, doesn't matter), you press a "share with others around you" button and anyone willing can see on their phone that <Name> is enjoying <this> song right now, they can then press on a song icon or a link and open it on their app. The same goes for videos that you watch, articles that you read, memes that you discover, etc. If you happen to like the content that someone else is enjoying, it's easy to reach out to them and start a conversation.